The technology described in this application relates to Fixed Wireless Access (FWA) and Fixed Wireless Terminals (FWT). Another name for FWT is Mobile Broadband Router (MBR). FWA provides an end user with fixed line services by utilizing a wireless technology, e.g., GSM, UMTS/HSPA/WCDMA, SAE/LTE, CDMA or WiMAX technologies. Fixed Wireless Terminals offer, for example, a cost efficient way to provide high speed data, voice, and fax services to small office/home office and residential users. The following description typically refers to the SAE/LTE technology as an example of wireless technology providing the backhaul connection to core and other networks. However, the technology may also be applied other access technologies like UMTS/HSPA/WCDMA and WiMAX.
A FWT device is for example located in an end user's home or office, normally in the same location all the time. There is no real mobility related to the FWT itself except “nomadicity” where the FWT could be powered off in one place, moved to another location and then powered on again. The FWT provides local connectivity and services for end user equipment located in the home using for example WLAN/WiFi or Ethernet as the media. In addition, the FWT may provide support for multiple legacy services. For example, a black phone (a good old fixed phone) or a fax can be connected to the FWT. The FWT is directly connected to the mobile operator's radio access and core networks and can for example provide access towards the Internet.
The technology also relates to a Generic Access Network (GAN) based on Unlicensed Mobile Access (UMA) specifications. GAN provides a new Radio Access Network (RAN) and includes Generic Access Network Controller (GANC). GAN is specified in the 3GPP TS 43.318 and TS 44.318. In GAN, a mobile station (MS) is a dual-mode, dual radio handset including for example both WiFi and 3GPP-macro radio support (GSM, WCDMA or both). The MS connects to a WiFi Access point (AP) using the WiFi radio and can also function in a GAN mode to access cellular radio services, e.g., provided by the GSM CN (Core Network).
Wireless access technologies, as opposed to wired technologies like Ethernet, will likely be used in the future in the home LAN, e.g., between the FWT and the home devices). WLAN/WiFi (e.g., the different variants of IEEE 802.11) will likely become a commodity in mobile terminals. As a result, the FWT device can be used to access Packet Switched (PS) services for mobile terminals. But known FWT solutions or products do not provide mobile terminals with the ability to use the FWT device and the Home LAN for mobile telephony. In other words, there is no way for the mobile terminal to access the mobile telephony services provided by the Circuit-Switched (CS) Core Network (CN), (e.g., a mobile switching center (MSC) node). This is a significant limitation of the FWT-based configurations because the existing CS CN services will likely be used for a very long time in the mobile networks as Voice-Over-Packet-Switched (PS) domain services (like IP Multimedia Services (IMS)) are still in their infancy. Accordingly, providing CS-domain based mobile telephony services as an integrated part of the FWT solutions is important for end users, mobile operators, and vendors.
Different approaches might be taken to allow mobile terminals to access and use CS-based mobile telephony CN services using FWT. For example, a UE could use IMS/SIP-signaling with the FWT, and the FWT could interwork that IMS/SIP-signaling with a CS-based mobile telephony service. A disadvantage with is approach is that the FWT services provided to the UE when in the IMS/SIP domain would be different from the services provided from the 3GPP CS domain. Any service interworking between an IMS/SIP-domain and the 3GPP CS domain is likely to be difficult to support in a transparent way. Another possible approach is to use a 3GPP macro network for CS access and FWT for data access. Drawbacks here include issues with the indoor voice coverage and the UE's simultaneous connection to both the 3GPP macro network and the local FWT network. The latter issue has a significant impact on UE battery lifetime. A better approach would be to connect simply to one of these networks at a time.